1. Field of Invention
The present invention relates to a fluorescent lamp and, in particular, to a fluorescent lamp that can adjust the color temperature of the light emitted therefrom.
2. Related Art
Recently, the energy saving awareness has become one of the hottest topics. For example, the traditional incandescent light bulbs have been substituted by the energy saving light bulbs gradually. The energy saving light bulbs in the market usually has a base and a spiral hot cathode lamp installed on the base. The appearance of the energy saving light bulb is similar to that of the traditional incandescent light bulb so that the energy saving light bulb can be used in the original lamp holder.
FIG. 1 shows a conventional energy saving light bulb 10 having a lamp 11 with a spiral structure. Two electrodes 12 are installed at two ends of the lamp 11 for connecting to the driver 13. The driver 13 is disposed inside a shell 14, and the shell 14 has a head 15 for coupling to an external lamp holder (not shown). Thus, the lamp holder can apply electric power to the driver 13. In addition, a cover 16 is disposed around the lamp 11 and connected to the shell 14.
However, the energy saving light bulb of FIG. 1 can only emit the light with a single color temperature, which is determined according to the fluorescent material disposed in the lamp 11. Thus, if the light source with different color temperature is needed, the light bulb must be changed, which causes inconveniences in usage.